code: def read_data_fast_batch(fn, batch_size, sep="\t"):
      import pandas
  
      for df in pandas.read_csv(
          fn, sep=sep, header=None, chunksize=batch_size
      ):
          yield np.ascontiguousarray(df.as_matrix(), dtype=np.float32)
  
file_path: nmslib/python_bindings/integration_tests/test_nmslib.py
imports: import sys
  import os
  import time
  import numpy
  import nmslib
  from common import *
label_desc: Use image node_id 3 for calling a global function with example usage: read_data_fast_batch(fn, batch_size, sep) without return types